1. Field of the Invention
The present invention generally relates to an electrical connector, and in particular to a double-shielded connector having excellent properties for shielding against electromagnetic interference (EMI).
2. The Prior Art
An electrical connector connects two devices together and transmits signals therebetween. To ensure proper signal transmission, a connector is provided with a shielding means for preventing the connector from being adversely affected by external electromagnetic interference (EMI). Related examples are disclosed in Taiwan Patent Application Nos. 85204902, 85208558, 85212192, 85215759 and 86214118. However, the conventional shielding means cannot completely shield the connector thereby resulting in poor EMI protection.
FIGS. 1 and 2 of the attached drawings show a conventional connector having a shielding means. The connector includes an insulative casing 1 comprising two tongue plates 11 and a partition plate 12 separating the two tongue plates 11 which support contact elements (not labeled) thereon. The shielding means comprises a rear shielding plate 2 and a front shielding member The rear shielding plate 2 defines a plurality of frames 21 for engaging with barbs 13 formed on the casing 1 thereby retaining the rear shielding plate 2 on the casing 1.
The front shielding member 3 comprises a housing 31 enclosing the casing 1 and having a plurality of resilient arms 312 stamped thereon thereby forming openings 311 associated with the arms 312. The resilient arms 312 serve to electrically and mechanically engage mating connectors coupled to the connector. The front shielding member 3 further comprises a U-shaped inner housing 32 which is fit over the partition plate 12 and retained thereon for electrically isolating the contact elements of the tongue plates 11. A number of resilient arms 322 are stamped on the inner housing 32 thereby forming openings 321 associated therewith.
However, the casing 1 is not completely shielded by the shielding means due to the openings 312, 321. Thus, proper signal transmission through the connector is not ensured.
Hence, it is desired to have an electrical connector providing excellent EMI protection.